Hand operated tube bender

ABSTRACT

The specification and drawings disclose a hand operated tube bender. The disclosed bender includes a pair of rigid frame members which are pivotally interconnected for oscillation about an intermediate axis. Portions of the frames on one side of the axis comprise operating handles to allow manual oscillation. Carried on one of the frames on the side of the axis opposite the handles is a forming roller with a peripheral, semi-circular groove sized to closely receive the outer circumference of a tube to be bent. Releasable lock means are carried on the roller for clamping a tube in the groove. Associated with the forming roller and carried on the same frame is a forming shoe having a generally semi-circular groove along one side and mounted to oscillate between a first lock position where it cooperates with the forming roller to closely engage the tube at the point of bend, and a second position where it is spaced from the forming roller to allow the tube to be inserted or removed. The forming roller is driven by a ratchet drive including a ratchet wheel drivingly connected to the forming roller and a pawl which is pivotally connected to the second frame and ocated so that when the frames are oscillated toward one another, a drive force is imparted to the forming roller.

ilnited States Patent 9] Dodge [54] HAND OPERATED TUBE BENDER [75Inventor: Harry G. Dodge, Painesville, Ohio [73] Assignee: CrawfordFitting Company, Solon,

Ohio

[22] Filed: Oct. 12, 197] Appl. No.: 188,489

Primary Examiner-Milton S. Mehr Attorney-Fay, Sharpe and Mulholland [451May 29,1973

[S7] ABSTRACT The specification and drawings disclose a hand operatedtube bender. The disclosed bender includes a pair of rigid frame memberswhich are pivotally interconnected for oscillation about an intermediateaxis. Portions of the frames on one side of the axis comprise operatinghandles to allow manual oscillation. Carried on one of the frames on theside of the axis opposite the handles is a forming roller with aperipheral, semi-circular groove sized to closely receive the outercircumference of a tube to be bent. Releasable lock means are carried onthe roller for clamping a tube in the groove. Associated with theforming roller and carried on the same frame is a forming shoe having agenerally semi-circular groove along one side and mounted to oscillatebetween a first lock position where it cooperates with the formingroller to closely engage the tube at the point of bend, and a secondposition where it is spaced from the forming roller to allow the tube tobe inserted or removed. The forming roller is driven by a ratchet driveincluding a ratchet wheel drivingly connected to the forming roller anda pawl which is pivotally connected to the second frame and ocated sothat when the frames are oscillated toward one another, a drive force isimparted to the forming roller.

7 Claims, 7 Drawing Figures PAIENIEWW 3.735.621

SHEET 1 OF 2 INVENTOR. HARRY G. DODGE ATTORNEYS PATENTEDW29|9753,735,621

SHEET 2 UF 2 HARRY 6 81 852 2 BY ay 5W 8 Mal/10M ATTORNEYS 1 HANDOPERATED TUBE BENDER The subject invention is directed to the art oftube bending tools and, more particularly, to an improved portable, handoperated tube bender.

Prior tube benders of the general type considered herein were typicallyrather difficult to operate. Moreover, after bending tubing in the priorbenders, the tubing in the area of the bend was often out-of-round byseveral thousanths of an inch. Also, it was generally difficult to bendthe tubing to the precise angle required.

The primary object of the invention is the provision of of a tube benderof the type described wherein the bending is accomplished duringactuation of a pair of handles toward one another. This allows the morepowerful of the arm and shoulder muscles to be used for applying thebending force. Also, it is generally much easier to control the extentof movement when moving levers or handles together than when moving themapart.

The invention also has for an object the provision of a tube benderwherein the tube is enclosed about substantially all 360 degrees of itscircumference at the point of bend during the bending operation, andwherein the tube can be released quickly and easily following thebending operation.

The above objects are achieved by a tube bender which comprises firstand second elongated bodies which are pivotally interconnected foroscillation about an intermediate axis. Portions of the bodies on afirstside of the axis serve as operating handles to permitthe bodies to bemanually oscillated. Mounted on the first body of the side of the axisopposite the handles is a forming roller having a peripheral,semi-circular groove size to receive a tube to be bent and releasablemeans to hold the tube in the groove. Associated with the forming rollerand carried on the same body is a forming shoe having a generallysemi-circular groove along one side and mounted to move between a firstlock position where it cooperates with the forming roller to closelyengage a tube to be bent, and a second position where it is spaced fromthe forming roller. A ratchet wheel is drivingly connected to theforming roller and a pawl is pivotally connected to the second body suchthat when the bodies are moved toward one another, a drive force isimparted to the forming roller. Preferably, the forming shoe is locatedbetween the axis of oscillation and the forming roller, andtheformingroller is rotated. in adirection such that-the tube bends away from theoperator.

The invention also contemplates that the forming shoe will preferably bemounted for pivotal movement about an axis parallel to, but spaced from,the first mentioned axis. Also, the lock means for the forming shoe ispreferably a simple lever carried in the forming shoe and adapted toengage a lock groove carried in the first body. This arrangement permitsrapid engagement and disengagement of the forming shoe.

The above and other objects and advantages will become apparent from thefollowing description when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a plan view of the preferred embodiment of a tube benderformed in accordance with the invention;

FIG. 2 is a side view partially in cross-section taken on line 2-2 ofFIG. 1;

FIG. 3 is a cross-sectional view taken on line 3-3 of FIG. 2;

FIG. 4 is a cross-sectional view taken on line 4-4 of FIG. 1;

FIG. Sis a cross-sectional view taken on line 5-5 of FIG. 1 and showingthe forming shoe lock mechanism in detail;

FIG. 6 is a view taken on line 6-6 of FIG. 1 showing the tube clampmechanism; and,

FIG. 7 is an enlarged cross-sectional view taken on line 77 of FIG. 1.

Referring more particularly to FIGS. 1 and 2, the overall arrangement ofthe tube bender is shown as including first and second pivotallyinterconnected rigid bodies 10 and 12 which are mounted for oscillationabout axis 14 which extends transversely through the bodies. Portions ofeach of the bodies on one side of the axis of oscillation 14 are formedto serve as operating handles. Note that body 10 includes an elongatedrelatively narrow portion 16 and the body 12 includes a similar portion18 which serve as manually actuable handles. The bodies can be made fromany suitable material and, of course, be one-piece or multiple-piececonstruction.

Carried from body 10 is a forming roller and tube clamp assembly 20which cooperate with a pivotally mounted forming shoe assembly 22. Theforming roller assembly will subsequently be described in substantialdetail; however, for the present, it is sufficient to note that theforming roller assembly 20 is drivingly rotated through a drive ratchetassembly 24 such that rotation of the roller takes place when thehandles 16 and 18 are oscillated toward one another.

As best shown in FIG. 2, the bodies 10 and 12 are pivotally connectedfor oscillation about axis 14 by a shaft 28 having a thin, enlarged head30. The left-hand end of shaft 28 (as viewed in FIG. 2) extends throughthe body 12 andis provided at its outer end with an enlargedflange orretaining disc 32 releasably connected to the shaft in anyconvenientmanner such as through the use of a socket head screw 34. Theamount of movement which the bodies 10 and 12 can take toward oneanother about axis 14 is limited by a stop pin 36 which is press fittedthrough body 10 and extends outwardly therefrom on both sides. As shownin FIG. 1, the pin engages the body 12 along its right-hand face toprevent further movement of the bodies toward one another.

The forming roll assembly 20 is pivotally mounted at the outer end ofbody 10 at a location spaced from axis 14 and on the side of the axisopposite the handle portion 16. As best seen in FIG. 2, assembly 20includes a forming rollmember 40 having a peripheral groove 42 ofsemi-circular cross-section and of a radius sized to closely receive theouter surface of a tube to be bent. Roll 40 has a laterally extendingshaft portion 44 which is carried in a sleeve bearing 46 extendingthrough body 10. A thin, flanged portion serves as a spacer between thebody 10 and the under-size of roll member 40. The left-hand end of shaft44 (as viewed in FIG. 2) is connected with the ratchet assembly 24 in amanner subsequently to be described. For the present however, attentionis directed to FIG. 1 where it is shown that a tube clamp 50 is carriedon the forming roll 40 for engaging the tube 52. The tube clamp 50 is ofthe type described and claimed in the commonly assigned US. Pat. No.3,433,042 which is incorporated herein by reference. Broadly, itincludes an arm 54 which is pivotally connected to the roller 40 by ashoulder bolt 56.

It will be noted that the roller 42 has a flat 58formed on the rightside thereof (as viewed in FIG. 1) and that the bolt 56 is arranged tohold the clamp arm 54 against the surface of the flat 58. The lower endof arm 54 (as viewed in FIG. 1) has a curved, downwardly extendingportion (best shown in FIG. 6). A slot or guide groove 60 is formedthrough the arm 54 and a lock jaw 62 is mounted therein for selectivemovement between the solid and dotted line positions shown in FIG. 6.Note that the lock jaw 62 has a total arcuate extent of slightly lessthan 180. Also, it has an inner contour 64 sized so as to closely engagethe outer surface of the tube 52. A guide pin extends from the backsurface of the locking jaw 62 through the slot 60 and a flange orshoulder 66 maintains the locking jaw properly positioned in the groovewhile permitting it to move between the solid and dotted line positionsof FIG. 6.

To use the tube clamp, the locking jaw 62 is moved to the dotted lineposition of FIG. 6 and the arm 54 pivoted upwardly so that the tubecan'be inserted adjacent the groove 42 of the forming roller. The tube,at the start of a bending operation, is shown in solid lines in FIG. 1.With the tube inserted, the arm is pivoted back down to the solid lineposition and the lock jaw 62 pivoted or slid back to its solid lineposition. The tube is thus loosely clamped in the groove 42.

Associated with the forming roll assembly 20 is the forming shoeassembly 22. Forming shoe assembly 22 serves to support the tube 52against the forming roll 40 and acts somewhat like an anvil during thebending operation. As best shown in FIGS. 1 and 2, the forming shoeassembly 22 includes a first bar 70 having an arcuate groove 72 formedalong one side thereof. Groove 72 has an arcuate extent of slightly lessthan 180 and a radius substantially corresponding to the radius of theouter surface of the tube 52. The preferred relationship between thegroove in the forming shoe and the forming roll is best seen in FIG. 7.Note that the forming roll groove is a perfect circle throughout 180.Tangents of 0.015 inches in length extend out from the end points. Thecross-section of the forming shoe groove is also a perfect circle butterminates 0.020 inches beyond the end of the tangents, thus providing0.005 inches for clearance.

The bar 70 is carried on a second pivotally mounted bar 74 and isreleasably connected thereto by machine screws or the like 76. Bar 70has a tongue portion 78 which is received in a groove 80 formed in bar74. As best shown in FIG. 1, bar 74 is pivotally connected to the bodyfor movement about an axis 82 which is parallel to the axis of rotationof the forming roll 40. Referring to FIG. 5, it is seen that the bar 74is connected to body 10 by a shaft 86 having a thin enlarged head 88. Adisc or the like 90 is releasably connected to the opposite end of shaft86 by a socket head screw 92 to maintain the bar 74 on the shaft whilepermitting free rotation. It should also be noted that a bearing 94having a thin flange 96 is positioned about the shaft 86 where it passesthrough body 10.

As shown in FIG. 1, the forming shoe assembly 22 is arranged so that itcan be moved between the solid line position where it cooperates withthe forming roll 40' for a bending operation, and to the dotted lineposition wherein the tube can be freely inserted and locked in positionon the forming roll or removed after the forming operation. The solidline position of the forming shoe assembly is a lock position and thelock means could take many forms but the preferred embodiment uses apivotally mounted locking lever best shown in FIGS. 1, 2 and 5.Referring in particular to FIG. 5, it will be seen that a lever 100 ispivotally mounted in bar 74 by a screw or shoulder bolt 102 whichextends through bar 74. The lever has an end portion 104 which extendsthrough a slot or groove 106 formed in bar 74. As shown, when pivoted tothe solid line position of FIG. 5, the portion 104 extends upwardlythrough the bar 74 into a slot or groove 107 carried in body 10. In,

the embodiment shown, the groove 107 is formed in a separate elementshown as a circular disc 108 carried in body 10. The disc 108 is merelypress fitted into an opening formed through the body. This facilitatesforming of the groove 107 and allows some adjustment of the groove asneeded during assembly of the appara- IUS.

When the lever 100 is pivoted to the dotted line position of FIG. 5, theportion 104 is withdrawn from the groove 107 and the forming shoe can beswung to the dotted line position of FIG. 1 for the insertion or removalof the tube.

The operation of the device thus far described is relatively simple.Note that the solid line showing of FIG. 1 illustrates the relationshipof the various parts at the start of a bend. To place the tube in thebender, the forming shoe assembly 22 is released from its lock positionand swung to the dotted line position. Also, the clamp arm is releasedby pivoting the lock member 62 and its pin shoulder 66 to the dottedline position of FIG. 6. The arm 54 is then swung up and the tube placedin position adjacent the forming roll 40. Thereafter, arm 54 is swungdown to the solid line position of FIG. 1 and the lock member rotated tothe solid line positions of FIGS. 1 and 6. Subsequently, the formingshoe assembly 22 is rotated to the solid line position of FIG. 1 andlocked therein. As can be appreciated, rotation of the forming roll 40in a counter-clockwise direction (as viewed in FIG. 1) causes theright-hand end of tube 52 to be bent upwardly as shown by 52, as it ispulled by the clamp assembly 50. The forming shoe assembly 22 holds theopposite end of the tube against the forming roll while the bend takesplace. It should be noted that the bending takes place at point and thatat this point, the tube is held substantially completely about itscircumference by the groove in the forming roll and the groove in theforming shoe (see FIG. 7). By controlling the amount of rotation offorming roll 40, the extent of the bend can be controlled. In thesubject embodiment, indicia in the form of score lines 122 are providedon the top of the forming roll 40 and a datum line 124 similarlyprovided on the top of the forming shoe assembly. The solid lineposition illustrates the start of the bend and, as can be appreciated,upon rotation to align different ones of these lines on the forming rollwith the datum line 124, the degree of bend can be closely controlled tosubstantially any desired angle.

The subject invention uses a ratchet drive mechanism for rotating theforming roll 40. The ratchet drive is arranged so that the drivingmovement takes place when the handles 16 and 18 are moved toward oneanother. This makes manual application of the forces required for thebending operation substantially easier than when the force must beexerted by pulling a pair of handles apart. This is so since it uses aset of arm and shoulder muscles which are generally much stronger.

Specifically, the ratchet drive mechanism includes a ratchet wheel 130which is connected to the shaft 44 in the manner best shown in FIGS. 1through 4. Note that the ratchet member 130 is received on a reduceddiameter outer end portion of shaft 44 and is maintained thereon indriving connection by a cap plate or disc 132 connected to shaft 44 by amachine screw 134. A pin 136 is press fitted into the cap plate 132 andextends into an opening 138 formed at the juncture between the internalbore of the ratchet 130 and the reduced diameter end portion of shaft44. This effectively keys the ratchet wheel to the shaft but permitseasy removal of the ratchet wheel for repair or replacement, ifnecessary. A spacer washer 140 is positioned between body and theratchet wheel 130 to maintain the ratchet wheel spaced outwardly a shortdistance from the body 10.

The ratchet wheel 130 is driven during oscillation of the arms by a pawl144 best shown in FIG. 3. Note that pawl 144 is pivotally connected tobody 12 by a pin 146. It should also be noted that the end of the pawlis received in a slot 148 formed in body 12. The end is bifurcated asbest shown in FIG. 2 and a spring 150 is positioned about the shaft 146and has its end portions bearing respectively against the pawl and theinner wall of the groove 148. This maintains the pawl continually biasedin a clockwise direction as viewed in FIG. 3. An adjustable stop pin 152extends through the pawl and engages the body 12 to limit the extent ofclockwise movement of the pawl.

As best shown in FIG. 3, the end of the pawl is provided with a tooth orthe like 154 which is adapted to engage the ratchet teeth 156. Note thatas the arm 18 is moved to the left (as viewed in FIG. 3), the pawl ismoved upwardly through the two dotted line positions until the portion154 is engaged with one of teeth 156 of the ratchet wheel 130. Thespring 150 maintains the pawl in engagement and the movement of arm 18in a counter-clockwise direction causes a rotating drive force to beapplied to the ratchet wheel driving the forming roll 40. At the end ofthe counter-clockwise movement of arm 18 as determined by the stop pin36, the stop pin 152 engages body 12 and withdraws the pawl from ratchetwheel 130.

The invention has been described in great detail sufficient to enableone of ordinary skill in the tube bending art to make and use the same.Obviously, modifications and alterations of the preferred embodimentwill occur to others upon a reading and understanding of thespecification and it is my intention to include all such modificationsand alterations as part of my invention insofar as they come within thescope of the appended claims.

What is claimed is:

I. A manually operable tube bender comprising:

first and second elongated rigid bodies pivotally interconnected foroscillation about a first axis having a fixed location with respect tosaid bodies with portions of the bodies on a first side of the firstaxis formed to serve as operating handles to allow the bodies to bemanually oscillated;

a forming roller having a peripheral, semi-circular groove sized toreceive a tube to be bent and rotatably mounted on the first body at alocation spaced from the axis on the side opposite the handles forrotation about a second axis extending parallel to the first axis;

a releasable tube clamp means carried on the roller and adapted to clampa tube in said groove;

a forming shoe carried on the same body as the forming roller and havinga generally semi-circular groove along one side and mounted to movebetween a first lock position to closely engage the tube to be bent, anda second position wherein it is spaced a substantial distance from theroller; and,

drive means for rotating said forming roller comprising a ratchet wheeldrivingly connected to said forming roller for rotation therewith aboutsaid second axis and a pawl member pivotally connected to the secondbody at a location such that when the handles are oscillated toward oneanother, a drive force is imparted to the forming roller.

2. The tube bender as defined in claim 1 wherein the forming shoe islocated between the first axis and the second axis.

3. The tube bender as defined in claim 1 wherein the forming shoe ismounted for pivotal movement about a third axis parallel to and spacedfrom the first axis.

4. The tube bender of claim 3 wherein means are provided for lockingsaid forming shoe in a first position substantially in engagement withsaid forming roller, said lock means comprising a lever carried in saidforming shoe and adapted to engage a groove formed in said first body.

5. The tube bender of claim 1 wherein said forming roller is carried ona shaft extending through said first body and wherein said ratchet wheelis connected to said shaft on the side of said body opposite saidforming roller.

6. The tube bender of claim 5 wherein said pawl member is pivotallyconnected to said second body and spring biased toward said ratchetwheel, and stop means for producing disengagement of said pawl from saidratchet wheel at the inner limit of oscillation of said bodies.

7. The tube bender of claim 6 wherein said releasable clamp means forholding a tube in the groove on said forming roller is pivotallyconnected to said forming roller for movement about an axis generallyperpendicular to said first axis.

k 4 I! l

1. A manually operable tube bender comprising: first and secondelongated rigid bodies pivotally interconnected for oscillation about afirst axis having a fixed location with respect to said bodies withportions of the bodies on a first side of the first axis formed to serveas operating handles to allow the bodies to be manually oscillated; aforming roller having a peripheral, semi-circular groove sized toreceive a tube to be bent and rotatably mounted on the first body at alocation spaced from the axis on the side opposite the handles forrotation about a second axis extending parallel to the first axis; areleasable tube clamp means carried on the roller and adapted to clamp atube in said groove; a forming shoe carried on the same body as theforming roller and having a generally semi-circular groove along oneside and mounted to move between a first lock position to closely engagethe tube to be bent, and a second position wherein it is spaced asubstantial distance from the roller; and, drive means for rotating saidforming roller comprising a ratchet wheel drivingly connected to saidforming roller for rotation therewith about said second axis and a pawlmember pivotally connected to the second body at a location such thatwhen the handles are oscillated toward one another, a drive force isimparted to the forming roller.
 2. The tube bender as defined in claim 1wherein the forminG shoe is located between the first axis and thesecond axis.
 3. The tube bender as defined in claim 1 wherein theforming shoe is mounted for pivotal movement about a third axis parallelto and spaced from the first axis.
 4. The tube bender of claim 3 whereinmeans are provided for locking said forming shoe in a first positionsubstantially in engagement with said forming roller, said lock meanscomprising a lever carried in said forming shoe and adapted to engage agroove formed in said first body.
 5. The tube bender of claim 1 whereinsaid forming roller is carried on a shaft extending through said firstbody and wherein said ratchet wheel is connected to said shaft on theside of said body opposite said forming roller.
 6. The tube bender ofclaim 5 wherein said pawl member is pivotally connected to said secondbody and spring biased toward said ratchet wheel, and stop means forproducing disengagement of said pawl from said ratchet wheel at theinner limit of oscillation of said bodies.
 7. The tube bender of claim 6wherein said releasable clamp means for holding a tube in the groove onsaid forming roller is pivotally connected to said forming roller formovement about an axis generally perpendicular to said first axis.